Rafael J. Wysocki | a9d7052 | 2009-06-10 01:27:12 +0200 | [diff] [blame] | 1 | /* |
| 2 | * kernel/power/suspend.c - Suspend to RAM and standby functionality. |
| 3 | * |
| 4 | * Copyright (c) 2003 Patrick Mochel |
| 5 | * Copyright (c) 2003 Open Source Development Lab |
| 6 | * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. |
| 7 | * |
| 8 | * This file is released under the GPLv2. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/string.h> |
| 12 | #include <linux/delay.h> |
| 13 | #include <linux/errno.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/console.h> |
| 16 | #include <linux/cpu.h> |
| 17 | #include <linux/syscalls.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 18 | #include <linux/gfp.h> |
Matthew Garrett | dd4c4f1 | 2010-05-28 16:32:14 -0400 | [diff] [blame] | 19 | #include <linux/io.h> |
| 20 | #include <linux/kernel.h> |
| 21 | #include <linux/list.h> |
| 22 | #include <linux/mm.h> |
| 23 | #include <linux/slab.h> |
| 24 | #include <linux/suspend.h> |
Rafael J. Wysocki | a9d7052 | 2009-06-10 01:27:12 +0200 | [diff] [blame] | 25 | |
| 26 | #include "power.h" |
| 27 | |
| 28 | const char *const pm_states[PM_SUSPEND_MAX] = { |
| 29 | [PM_SUSPEND_STANDBY] = "standby", |
| 30 | [PM_SUSPEND_MEM] = "mem", |
| 31 | }; |
| 32 | |
| 33 | static struct platform_suspend_ops *suspend_ops; |
| 34 | |
| 35 | /** |
| 36 | * suspend_set_ops - Set the global suspend method table. |
| 37 | * @ops: Pointer to ops structure. |
| 38 | */ |
| 39 | void suspend_set_ops(struct platform_suspend_ops *ops) |
| 40 | { |
| 41 | mutex_lock(&pm_mutex); |
| 42 | suspend_ops = ops; |
| 43 | mutex_unlock(&pm_mutex); |
| 44 | } |
| 45 | |
| 46 | bool valid_state(suspend_state_t state) |
| 47 | { |
| 48 | /* |
| 49 | * All states need lowlevel support and need to be valid to the lowlevel |
| 50 | * implementation, no valid callback implies that none are valid. |
| 51 | */ |
| 52 | return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); |
| 53 | } |
| 54 | |
| 55 | /** |
| 56 | * suspend_valid_only_mem - generic memory-only valid callback |
| 57 | * |
| 58 | * Platform drivers that implement mem suspend only and only need |
| 59 | * to check for that in their .valid callback can use this instead |
| 60 | * of rolling their own .valid callback. |
| 61 | */ |
| 62 | int suspend_valid_only_mem(suspend_state_t state) |
| 63 | { |
| 64 | return state == PM_SUSPEND_MEM; |
| 65 | } |
| 66 | |
| 67 | static int suspend_test(int level) |
| 68 | { |
| 69 | #ifdef CONFIG_PM_DEBUG |
| 70 | if (pm_test_level == level) { |
| 71 | printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); |
| 72 | mdelay(5000); |
| 73 | return 1; |
| 74 | } |
| 75 | #endif /* !CONFIG_PM_DEBUG */ |
| 76 | return 0; |
| 77 | } |
| 78 | |
| 79 | /** |
| 80 | * suspend_prepare - Do prep work before entering low-power state. |
| 81 | * |
| 82 | * This is common code that is called for each state that we're entering. |
| 83 | * Run suspend notifiers, allocate a console and stop all processes. |
| 84 | */ |
| 85 | static int suspend_prepare(void) |
| 86 | { |
| 87 | int error; |
| 88 | |
| 89 | if (!suspend_ops || !suspend_ops->enter) |
| 90 | return -EPERM; |
| 91 | |
| 92 | pm_prepare_console(); |
| 93 | |
| 94 | error = pm_notifier_call_chain(PM_SUSPEND_PREPARE); |
| 95 | if (error) |
| 96 | goto Finish; |
| 97 | |
| 98 | error = usermodehelper_disable(); |
| 99 | if (error) |
| 100 | goto Finish; |
| 101 | |
| 102 | error = suspend_freeze_processes(); |
| 103 | if (!error) |
| 104 | return 0; |
| 105 | |
| 106 | suspend_thaw_processes(); |
| 107 | usermodehelper_enable(); |
| 108 | Finish: |
| 109 | pm_notifier_call_chain(PM_POST_SUSPEND); |
| 110 | pm_restore_console(); |
| 111 | return error; |
| 112 | } |
| 113 | |
| 114 | /* default implementation */ |
| 115 | void __attribute__ ((weak)) arch_suspend_disable_irqs(void) |
| 116 | { |
| 117 | local_irq_disable(); |
| 118 | } |
| 119 | |
| 120 | /* default implementation */ |
| 121 | void __attribute__ ((weak)) arch_suspend_enable_irqs(void) |
| 122 | { |
| 123 | local_irq_enable(); |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * suspend_enter - enter the desired system sleep state. |
| 128 | * @state: state to enter |
| 129 | * |
| 130 | * This function should be called after devices have been suspended. |
| 131 | */ |
| 132 | static int suspend_enter(suspend_state_t state) |
| 133 | { |
| 134 | int error; |
| 135 | |
| 136 | if (suspend_ops->prepare) { |
| 137 | error = suspend_ops->prepare(); |
| 138 | if (error) |
| 139 | return error; |
| 140 | } |
| 141 | |
| 142 | error = dpm_suspend_noirq(PMSG_SUSPEND); |
| 143 | if (error) { |
| 144 | printk(KERN_ERR "PM: Some devices failed to power down\n"); |
| 145 | goto Platfrom_finish; |
| 146 | } |
| 147 | |
| 148 | if (suspend_ops->prepare_late) { |
| 149 | error = suspend_ops->prepare_late(); |
| 150 | if (error) |
| 151 | goto Power_up_devices; |
| 152 | } |
| 153 | |
| 154 | if (suspend_test(TEST_PLATFORM)) |
| 155 | goto Platform_wake; |
| 156 | |
| 157 | error = disable_nonboot_cpus(); |
| 158 | if (error || suspend_test(TEST_CPUS)) |
| 159 | goto Enable_cpus; |
| 160 | |
| 161 | arch_suspend_disable_irqs(); |
| 162 | BUG_ON(!irqs_disabled()); |
| 163 | |
| 164 | error = sysdev_suspend(PMSG_SUSPEND); |
| 165 | if (!error) { |
| 166 | if (!suspend_test(TEST_CORE)) |
| 167 | error = suspend_ops->enter(state); |
| 168 | sysdev_resume(); |
| 169 | } |
| 170 | |
| 171 | arch_suspend_enable_irqs(); |
| 172 | BUG_ON(irqs_disabled()); |
| 173 | |
| 174 | Enable_cpus: |
| 175 | enable_nonboot_cpus(); |
| 176 | |
| 177 | Platform_wake: |
| 178 | if (suspend_ops->wake) |
| 179 | suspend_ops->wake(); |
| 180 | |
| 181 | Power_up_devices: |
| 182 | dpm_resume_noirq(PMSG_RESUME); |
| 183 | |
| 184 | Platfrom_finish: |
| 185 | if (suspend_ops->finish) |
| 186 | suspend_ops->finish(); |
| 187 | |
| 188 | return error; |
| 189 | } |
| 190 | |
| 191 | /** |
| 192 | * suspend_devices_and_enter - suspend devices and enter the desired system |
| 193 | * sleep state. |
| 194 | * @state: state to enter |
| 195 | */ |
| 196 | int suspend_devices_and_enter(suspend_state_t state) |
| 197 | { |
| 198 | int error; |
Rafael J. Wysocki | 452aa69 | 2010-03-05 13:42:13 -0800 | [diff] [blame] | 199 | gfp_t saved_mask; |
Rafael J. Wysocki | a9d7052 | 2009-06-10 01:27:12 +0200 | [diff] [blame] | 200 | |
| 201 | if (!suspend_ops) |
| 202 | return -ENOSYS; |
| 203 | |
| 204 | if (suspend_ops->begin) { |
| 205 | error = suspend_ops->begin(state); |
| 206 | if (error) |
| 207 | goto Close; |
| 208 | } |
| 209 | suspend_console(); |
Rafael J. Wysocki | 452aa69 | 2010-03-05 13:42:13 -0800 | [diff] [blame] | 210 | saved_mask = clear_gfp_allowed_mask(GFP_IOFS); |
Rafael J. Wysocki | a9d7052 | 2009-06-10 01:27:12 +0200 | [diff] [blame] | 211 | suspend_test_start(); |
| 212 | error = dpm_suspend_start(PMSG_SUSPEND); |
| 213 | if (error) { |
| 214 | printk(KERN_ERR "PM: Some devices failed to suspend\n"); |
| 215 | goto Recover_platform; |
| 216 | } |
| 217 | suspend_test_finish("suspend devices"); |
| 218 | if (suspend_test(TEST_DEVICES)) |
| 219 | goto Recover_platform; |
| 220 | |
| 221 | suspend_enter(state); |
| 222 | |
| 223 | Resume_devices: |
| 224 | suspend_test_start(); |
| 225 | dpm_resume_end(PMSG_RESUME); |
| 226 | suspend_test_finish("resume devices"); |
Rafael J. Wysocki | 452aa69 | 2010-03-05 13:42:13 -0800 | [diff] [blame] | 227 | set_gfp_allowed_mask(saved_mask); |
Rafael J. Wysocki | a9d7052 | 2009-06-10 01:27:12 +0200 | [diff] [blame] | 228 | resume_console(); |
| 229 | Close: |
| 230 | if (suspend_ops->end) |
| 231 | suspend_ops->end(); |
| 232 | return error; |
| 233 | |
| 234 | Recover_platform: |
| 235 | if (suspend_ops->recover) |
| 236 | suspend_ops->recover(); |
| 237 | goto Resume_devices; |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * suspend_finish - Do final work before exiting suspend sequence. |
| 242 | * |
| 243 | * Call platform code to clean up, restart processes, and free the |
| 244 | * console that we've allocated. This is not called for suspend-to-disk. |
| 245 | */ |
| 246 | static void suspend_finish(void) |
| 247 | { |
| 248 | suspend_thaw_processes(); |
| 249 | usermodehelper_enable(); |
| 250 | pm_notifier_call_chain(PM_POST_SUSPEND); |
| 251 | pm_restore_console(); |
| 252 | } |
| 253 | |
| 254 | /** |
| 255 | * enter_state - Do common work of entering low-power state. |
| 256 | * @state: pm_state structure for state we're entering. |
| 257 | * |
| 258 | * Make sure we're the only ones trying to enter a sleep state. Fail |
| 259 | * if someone has beat us to it, since we don't want anything weird to |
| 260 | * happen when we wake up. |
| 261 | * Then, do the setup for suspend, enter the state, and cleaup (after |
| 262 | * we've woken up). |
| 263 | */ |
| 264 | int enter_state(suspend_state_t state) |
| 265 | { |
| 266 | int error; |
| 267 | |
| 268 | if (!valid_state(state)) |
| 269 | return -ENODEV; |
| 270 | |
| 271 | if (!mutex_trylock(&pm_mutex)) |
| 272 | return -EBUSY; |
| 273 | |
| 274 | printk(KERN_INFO "PM: Syncing filesystems ... "); |
| 275 | sys_sync(); |
| 276 | printk("done.\n"); |
| 277 | |
| 278 | pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); |
| 279 | error = suspend_prepare(); |
| 280 | if (error) |
| 281 | goto Unlock; |
| 282 | |
| 283 | if (suspend_test(TEST_FREEZER)) |
| 284 | goto Finish; |
| 285 | |
| 286 | pr_debug("PM: Entering %s sleep\n", pm_states[state]); |
| 287 | error = suspend_devices_and_enter(state); |
| 288 | |
| 289 | Finish: |
| 290 | pr_debug("PM: Finishing wakeup.\n"); |
| 291 | suspend_finish(); |
| 292 | Unlock: |
| 293 | mutex_unlock(&pm_mutex); |
| 294 | return error; |
| 295 | } |
| 296 | |
| 297 | /** |
| 298 | * pm_suspend - Externally visible function for suspending system. |
| 299 | * @state: Enumerated value of state to enter. |
| 300 | * |
| 301 | * Determine whether or not value is within range, get state |
| 302 | * structure, and enter (above). |
| 303 | */ |
| 304 | int pm_suspend(suspend_state_t state) |
| 305 | { |
| 306 | if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) |
| 307 | return enter_state(state); |
| 308 | return -EINVAL; |
| 309 | } |
| 310 | EXPORT_SYMBOL(pm_suspend); |